题目内容：

Gmat 语法题求答案
71. Unlike the original National Museum of Science and
Technology in Italy, where the models are encased in
glass or operated only by staff members, the Virtual
Leonardo Project, an online version of the museum,
encourages visitors to “touch” each exhibit, which
thereby activates the animated functions of the piece.
(A) exhibit, which thereby activates
(B) exhibit, in turn an activation of
(C) exhibit, and it will activate
(D) exhibit and thereby activate
(E) exhibit which, as a result, activates
答案说是which前必须有先行词,但是如果选A似乎which也可以用来修饰小句
Leonardo Project, an online version of the museum,
encourages visitors to “touch” each exhibit.
希望高人指教!
答案是选D which是应该修饰紧跟的先行词 但是选A也可以理解成修饰前面的小句啊